Piston skirt expander



April 4, 1939. H. P. PHILLIPS PISTON SKIRT EXPANDER Filed Aug. 25, 1957 INVENTOR. flare/a Fwy/w Q M15 w /M M ATTORNEY$ Patented Apr. 4, 1939 UNITED STATES PISTON SKIRT EXPANDER Harold P. Phillips, Webster Groves, Mo., assignor to Hastings Manufacturing Company, Hastings, Mich., a corporation of Michigan Application August 25, 1937, Serial No. 160,769

6 Claims.

The main objects of this invention are to provide a piston skirt expander which is simple and inexpensive in. construction, easily installed, and very efiicient.

A further object is to provide a piston skirt expander which while exerting the desired expansive force on a skirt piston, will yield under conditions such as substantial increase in temperature of the piston in use.

Objects relating to details and economies of the invention will appear from the description to follow. The invention is defined and pointed out in the claims.

A preferred embodiment of the invention is illustrated in the accompanying drawing, in

which:

Fig. 1 is a transverse section of a piston having one of my improved expanders installed therein, taken on the broken line l-l of Fig. 2.

Fig. 2 is a fragmentary side elevation of the piston with an expander embodying my invention installed therein.

Fig. 3 is a perspective view of a preferred embodiment of my invention.

Fig. 4 is a perspective View of a modified form or embodiment.

Fig. 5 is a longitudinal section of one of a coacting pair of expander members.

Fig. 6 is a longitudinal section of one of a pair of expander members showing a modification thereof.

, Fig. 7 is a central transverse section of one of the expander members.

In the accompanying drawing, I have conventionally illustrated a split skirt piston I, the skirt 2 thereof having a longitudinal split 3 providing a slot 4. My improved expander is designed to be inserted or seated in this slot to exert expansive force thereon while permitting collapsing movement under such conditions, as the heating of the piston in use.

My expander comprises a pair of bowed spring members 5 and 6 which in the preferred embodiment are connected at their rear edges by the strap 1 which projects beyond the rear edges. The members 5 and 6 are arranged in back to back relation and contacting at a central point as at 8 so that their ends diverge outwardly and in effect provide four spring arms. These spring expander members are inserted in the slot of the split piston skirt 2, indicated in Figs. 1 and 2, with the arms of the members partially collapsed so that they exert a spring expanding action on the skirt. These members 5 and 6 are preferably provided with longitudinal grooves 9 at at least one end, these grooves being adapted to receive the edges ll] of the slot in the piston skirt.

Preparatory to inserting the expander, a section or zone H of the skirt walls is beveled or cut away providing relatively sharp edges l2 5 adapted to engage in the grooves 9. These grooves are desirable in that they effectively space the outer edges of the expander members relative to the peripheral surface of the piston-that is, they lie within the periphery of the piston so that 10 they cannot contact with the cylinder wall.

In the embodiment of my invention shown in Figs. 4, 5 and 6, the tie member is omitted. In the embodiment shown in Fig. 6, the grooves 9 are provided at each end of the member. Where 16 the members are connected by the ties or straps 1, the groove may be formed in one member only and the device be easily positioned. Owing to their shape, there is a tendency for the end edges of the expander members to bight into the edges 20 of the skirt groove and this also assists in retaining the expander in its adjusted position.

I have not attempted in the accompanying drawing to illustrate the parts in their relative proportions and the expander members are shown 25 as formedof considerably thicker stock and relatively Wider than they are in practice but this is done for convenience in illustration. Proper proportioning will be readily understood by those skilled in the art to which this invention relates. 30

I have illustrated and described my improvements in an embodiment which I have found very satisfactory. I have not attempted to illustrate or describe certain other embodiments or adaptations as it is believed that this disclosure will enable those skilled in the art to which my invention relates to embody or adapt the same as may be desired.

Having thus described my invention, what I claim as new and desire to secure by Letters Patent, is:

1. A piston expander comprising longitudinally bowed spring members disposed to face oppositely in back to back supporting engagement, said 45 members being joined at their rear edges by an integral tie portion with both ends projecting beyond the ends of the tie portion, one end of each spring member being grooved for engagement with the edges of a split in a split piston 50 skirt.

2. A piston expander comprising longitudinally bowed spring members disposed to face oppositely in back to back supporting engagement, one end of each spring member being grooved for engage- 55 5. In combination, a piston skirt provided with a slot, and an expander comprising a pair of oppositely bowed. spring members arranged in supporting engagement within the slot, said members being formed integrally and having a central connecting strap at their rear edges.

6. A piston expander comprising longitudinally oppositely bowed spring members disposed in opposed supporting engagement, each spring member being grooved for engagement with the 10 split edges of a split piston skirt.

HAROLD P. PHILLIPS. 

